With the development of mobile communications, a traditional macro cellular network cannot satisfy an increasing requirement of a user service rate any more. Therefore, in order to increase a data transmission rate and prevent occurrence of a coverage hole, a growing number of low power nodes (LPNs, low power nodes) will be deployed in a wireless network, so as to ensure quality of service (QoS, quality of service) for users and improve network performance.
A main purpose of deploying the LPNs is to cover a hotspot, that is, to enable more users to find some low power nodes in a surrounding environment as soon as possible and access or camp on the low power nodes as soon as possible, thereby implementing proper use of network resources and load balance. Because of a network deployment requirement of an operator, a large cell range extension (CRE, Cell Range extension) factor is introduced for LPNs, so that users can identify the LPNs as soon as possible to access or camp on the LPNs. However, such a solution also causes serious network interference, especially interference of a micro base station with edge users within coverage of the LPNs.
At present, the foregoing interference is generally canceled in the following two modes:
First interference cancellation mode: An inter-cell interference cancellation (ICIC, Inter-cell Interference Cancellation) manner or an inter-cell interference cancellation (eICIC, Enhanced Inter-cell Interference Cancellation) manner is used on a network side to assist in reducing interference with a user terminal. For example, an almost blank subframe (ABS, Almost Blank Subframes) policy is used in the eICIC solution. However, assistance in reducing interference with a user terminal on the network side is applicable only to small CRE (less than or equal to 6 dB) and is not applicable to CRE greater than 6 dB.
Second interference cancellation mode: An interference cancellation (IC, Interference Cancellation) algorithm is used on a user terminal side to directly cancel interference. That is, an original signal is recovered by estimating a signal of a strongest interfering cell and then subtracting, on a receiving terminal, the estimated interfering signal from a received signal that includes interference. However, an interference cancellation effect on the user terminal side entirely depends on accuracy of estimation of a signal of an interfering cell.
However, in research on and practice of the prior art, the inventor of the present invention finds that in an existing implementation manner, when a user terminal performs interference cancellation, specific physical channels, signals, or messages such as a PCFICH, a PDCCH, a PBCH, a PCH, an SIB message, a PSS, or an SSS of a specific cell (including a serving cell or an intra-frequency neighboring cell) cause main interference received by the user terminal, but the user terminal does not know exactly power transmission strength of these specific physical channels, signals, or messages of the interfering cell; therefore, a user can only blindly estimate these specific physical channels, signals, or messages of the strong interfering cell, resulting in large deviation during estimation and reconstruction of an interfering signal and seriously affecting interference cancellation performance of a user equipment.